Method of making filament mounts



Dec. 14, 1954 J. FLAws, JR.. ET AL. 2,696,849

METHOD OF MAKING FILAMENT MOUNTS Original Filed March 31. 1950 lnven tors: John FLaws Jr:, John W. ATWIShOTWH, 8 WK Their- A t tovneg.

United States Patent METHOD OF MAKING FILAMENT MOUNTS John Flaws, Jr., East Cleveland, and John W. Anthony, Cleveland Heights, Ohio, assignors to General Electric Company, a corporation of New York; patent dedicated to the Public insofar as it relates to lamps and lamp parts to the extent stated in document recorded in the United States Patent Office, January 4, 1954, Liber U-238, page 394 Original application March 31, 1950, Serial No. 153,076. and this application June 25, 1952, Serial No.

2 Claims. (Cl. 14071.5)

Our invention relates to a method of making filament mounts for incandescent lamps and the like. More particularly, our invention relates to a method especially suited to the manufacture of small and very compact filament mounts. This application is a division of our application Serial No. 153,076, filed March 31, 1950.

Heretofore, the manufacture of certain very complex and compact filament mounts for small multiple or higher voltage incandescent lamps used for night-lights, Christmas tree decoration, etc. has been restricted to manual filament mounting operations. This manner of operation was necessitated because of the difficulty of draping a relatively long coiled filament over support wires at offset relations to each other and of attaching said filament to leading-in wires offset from adjacent support wires. The size of the mount also contributes to the difiiculty of manufacture because the smaller mounts do not have sufficient clear space in the region of the support and leading-in wires to accommodate automatic apparatus.

One object of our invention is to provide a method of manufacturing filament mounts for lamps, which method is particularly adapted to make a mount having a relatively long filament attached to support and leadingin wires at alternately offset positions.

Another object of our invention is to provide a method of forming concentrated filament mounts for lamps by first manufacturing a relatively large and widely spread mount, which may be done conveniently on conventional automatic equipment, and then re-forming said mount to the desired shape by a novel sequence of steps. The method and means of our invention permits the use of existing well developed apparatus in the initial steps of forming the mount and provides for the reshaping of said mount by operations capable of being performed by mechanical means. The first steps in the manufacture provide for the construction of a mount comprising a supporting body, in the form of a vitreous stem, and of leading-in and support wires retained by said stem and extending to spaced portions of a filament located beyond the end of the stem. In succeeding re-forming steps the leading-in wires and the support wires of the mount are bent so that the ends thereof supporting the various portions of the filament are relocated at different positions relative to the stem. The re-forming steps of the method provide for the manufacture of one form of mount, for example, by bending the extending ends of the leading-in wires and certain support wires to positions nearer the stern and by so doing position the filament nearer to and around at least a part of said stem. The arrangement of the leading-in and support wires is such that the ends of alternate wires around the stem are offset longitudinally from each other relative to the stem and the filament accordingly has a zig-zag form.

Still another object of our invention is to provide a method which includes bending a fold or so-called loopback section in the leading-in and support wires of a mount so as to reduce the effective length of said wires and position the connected portions of the filament nearer the stem. The above operations are performed Without injury to the filament and are particularly adapted to develop the compact mount forms necessary for insertion into small size bulbs and bulbs having small necks.

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The fold or loop-back bend is made in the leading-in and support wires by forming a bend in the portions thereof adjacent the stem and in intermediate portions thereof, the operations being performed in such a manner that the extending ends of the leading-in and support wires are properly relocated.

Still other objects and advantages of our invention will appear in the following detailed disclosure.

In the drawing, Figs. 1 to 5 are perspective views, on an enlarged scale (several times larger than actual size), of a lamp mount during various steps in the reformation thereof in accordance with our invention.

The manufacture of a mount in accordance with the invention provides, first, for the incorporation of the various elements thereof into a uniform and readily obtainable mount assembly, and then the reformation or reshaping of the assembly into a mount of the complex character and much reduced spread desired. The first steps in the method are preferably performed in one of the various forms of lamp making apparatus presently in use; whereas, the re-forming steps in the method preferably occur in apparatus such as that disclosed in our aforesaid copending application Serial No. 153,076, filed March 31, 1950. The lamp mount 1 as initially made, preferably on conventional automatic equipment, appears as shown in Fig. 1 and comprises a main supporting body, the tipless type stem tube 6; the exhaust tube 7; the current conductors, the leading-in wires 8 and 9; the stem arbor 10, the support wires 11, 12, and 13; and the U-shaped coiled filament 14. The lamp mount 1 is held with the filament 14 lowermost. The filament has opposite ends clamped in hooks in the extending ends of the leading-in wires 8 and 9 and is supported at spaced intermediate points by the support wires 11, 12 and 13. The mount 1 is of relatively open construction with said filament 14 located in a plane beyond the end of the stem tube 6 and arbor 10. This particular filament mount 1 is that made by the apparatus disclosed in Patent 1,907,532, Flaws, and illustrates the general type of filament mount suitable to re-formation by our method. However, it will be understood that our invention is not restricted to a filament mount 1 of this exact construction, size, shape, or proportions. The filament 14 of the mount 1 extends laterally outward an amount permitting its use in many lamps but is so large as to prevent its insertion into and operation in the smaller size bulbs of many low wattage night-light and decorative types of lamps.

Re-formation or reshaping of the mount 1 is initiated by repositioning the leading-in wires 8 and 9 in the manner shown in Fig. 2. The ends of the leading-in wires 8 and 9 are bent around to positions closer to each other and take positions causing the filament 14 to be pulled taut around the support wires 11, 12 and 13. The following step in the reshaping of the mount 1 consists in bending the extending looped ends of the outer support wires 11 and 13 around to positions at opposite sides of the mount 1 and in a plane through the center thereof. This bending operation also positions the looped ends of the support wires 11 and 13 closer to the arbor 10. The bending operation moves the support wires 11 and 13 from positions at of either side of support wire 12 to positions therefrom and by so doing reduces the spread of the mount and the filament 14 which again becomes loosely held as shown in Fig. 3. The succeeding operations of the method comprise bending the ends of the leading-in wires 8 and 9 clamped to the filament 14 upward and inward (Fig. 4) to the elevation of a horizontal plane through the end button on the arbor 10 and to positions closer to the longitudinal center of the mount 1. These operations, which are performed by means moved upward against intermediate portions of the Wires 8 and 9, make a so-called loop-back bend in each leading-in wire 8, 9 and considerably reduce the spread of the filament mount 1 in the plane perpendicular to that of the support wires 11 and 13. The filament 14 is still loosely held in the mount 1 as the ends of the leading-in wires 8 and 9 are still at substantially the same distance from the loops in the support wires 11 and 13. The final shaping of the mount causes an intermediate portion of the support wire 12 to be pushed upward so that the looped end thereof is bent upward and inward toward the end of the arbor 10. The mount 1 is further reduced in spread by this operation and the filament 14- is placed under moderate tension. The mount 1 then appears as shown in Fig. 5 and is in a compact form well suited to eificient operation in lamps for many practical purposes. A one-third reduction occurs in the spread of the mount in the course of the above-described operations and said mount 1 is now of equal width and breadth. The illustrated mount 1 has only inch spread and, accordingly, would be difficult to manufacture on a commercial scale by other means.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. The method of reshaping an incandescent lamp mount comprising a stern having an arbor projecting axially therefrom and a pair of spaced leading-in wires projecting from said stem at an acute angle to its axis and extending to a transverse plane adjacent the end of said arbor, and three support wires anchored in said arbor and extending radially outward away from said leading-in wires and with their free ends located substantially in said plane, and a horseshoeshaped coiled filament in said plane and secured at its ends to the free ends of said leading-in wires and supported at spaced points intermediate its ends by loops in said support wires, which method comprises bending the two support wires located next adjacent the leading-in wires about points adjacent their anchored ends and in directions toward the stern axis to relocate their looped ends beyond the said plane and reduce the spread thereof, and then reshaping the leading-in wires and the third support wire to displace them inwardly toward the stern axis and with their free ends located out of said plane toward the stem by bending intermediate portions of the said wires into loops extending back longitudinally of the stem to thereby decrease the lateral extent of the mount so it may be inserted in a bulb of restricted proportions.

2. The method of reshaping an incandescent lamp mount comprising a stern having an arbor projecting axially therefrom and a pair of spaced leading-in wires projecting from said stem at an acute angle to its axis and extending to a transverse plane adjacent the end of said arbor, and an odd numbered plurality of support wires anchored in said arbor and extending radially outward. away from said leading-in wires and with their free ends located substantially in said plane, and a horseshoe-shaped coiled filament in said plane and secured at its ends to the free ends of said leading-in wires and supported at spaced points intermediate its ends by loops in said support wires, which method comprises bending alternate ones of said support wires about points adjacent their anchored ends and in directions toward the stem axis to relocate their looped ends beyond the said plane and reduce the spread thereof, and then reshaping the remaining leading-in and support wires to displace them inwardly toward the stem axis and with their free ends located out of said plane toward the stern by bending intermediate portions of the said wires into loops extending back longitudinally of the stem to decrease the lateral extent of the mount so it may be inserted in a bulb of restricted proportions.

References Cited in the tile of this patent UNITED STATES PATENTS Number Name Date 2,085,578 Flaws June 29, 1937 2,145,911 Anderson Feb. 7, 1939 2,208,970 Geiger July 23, 1940 2,380,742 Flaws July 3l, 1945 2,575,771 Russell Nov. 20, 1951 

